Coding systems for mutual association of different components, including visual or color coding systems, are widely used in a plurality of industrial applications.
Also, there are several types of coding systems to identify numberings or intended functions of conductor wires of a cable by colors. For example, coding systems are known which are intended to facilitate correct wiring.
Accordingly, in three-wire cables, for example, in which one of the wires is marked in red, one of the wires in black, and one of the wires is marked in green/yellow, for example, the red wire should always be connected with ‘+’, the black wire with ‘−’, and the green/yellow wire should always be connected to ground.
Furthermore, another color coding for identifying wires of telecommunication cables is given by DIN 47100, for example, which although withdrawn is still often used.
Also, a 25-pair-color labeling is known, for identifying individual conductor or wirers in electrical telecommunication cables. This labeling is also referred to as “twisted-pair cabling” and is usually applied to RJ21 cables. For identification purposes, the colors are applied to the wire insulation. For each twisted pair of wires, a first color is selected from a first group of five colors and a second color is selected from a second group of five colors, so that in total 25 combinations of two colors are formed.
Moreover, it is known to mark cables that combine a plurality of wires with different colors, for example blue and green network cables. Again, this is intended to allow the user to quickly identify which components are to be connected or are connected with which cables.
Furthermore, it is known from DE 40 16 445 A1, for example, to identify both the wires bundled in cables and the cables themselves with different colors, to thereby distinguish the cables from each other and moreover easily identify the wires within a cable.
Accordingly, besides simplifying the allocation of individual wires to be connected in a circuit, it is additionally possible in this manner to more easily allocate a first color-coded cable to a first circuit and a second color-coded cable to a second circuit.
Furthermore, from DE 43 95 807 T1 it is known to bundle a plurality of such cables in a wiring harness and to provide the latter with a label, and/or to provide individually cut lengths of the wiring harness with appropriate connectors for each cable and for the wires or conductors included therein.
It is furthermore known, as part of wiring automation systems, also referred to as system wiring below, to bundle the conductor wires for transmitting input/output signals (I/O signals) between an input/output module (I/O module) of an automation device for coupling an external device to a control unit and this external device by means of a common connector pluggable into the I/O module, and then to route the conductor wires from the connector plugged into the I/O module to the external device either in a single cable or as a bundle of individual wire. In this case, the I/O module itself may perform signal control and/or signal processing functions as well. For this purpose, these signal control and/or signal processing functions may be included in a pluggable input/output card (I/O card), for example, which is accommodated by the I/O module and on which these functions are stored in hardware (e.g. hard-wired) and/or in software (e.g. by means of a programmable logic controller “PLC”). Depending on the specific implementation, the I/O signals may comprise analog signals and/or digital signals in this case.
External devices, also referred to as peripheral modules below, may in particular include modules with pluggable relays and other modules, but also field devices such as actuators and sensors. An example for a module with pluggable relay that may be mentioned is the module marketed by the applicant under the designation “V8 adapter”.
The connection to the external devices is then made either through terminals, e.g. with spring-cage connection or screw connection or with insulation displacement terminals, or via connector systems such as the so-called D-SUB connector system for data connections, and other proprietary connector systems.
Now, one problem is, for example, that for wiring solutions often the assignment of the wires is considerably more difficult, the more conductor wires are required for signal transmission between an input/output module (I/O module) of an automation device and an external device, which may ultimately result in wiring errors and thus may cause malfunction of the automation system.
For example, if 32 or even more conductor wires wires are to be connected between an input/output module (I/O module) of an automation device and an external device, alone in case of 32 conductor wires which have one conductor wire end connected to the I/O module, there are already 528 connection possibilities for identifying the conductor wires ends at the end of the external device in a specific order and connecting them according to a predetermined wire assignment. This is because first one conductor wire has to be identified from 32 conductor wires, then another conductor wire from the remaining 31 conductor wires, and so on.
Therefore, already nowadays 8 to 10 individual wires are preferably combined and provided with a cable jacket. In case of a total of 40 individual wires with one end of each conductor wire connected to the I/O module, these wires can be bundled into e.g. 4 cables emanating from the I/O module, each cable with at least one connector for being connected to an external device, and in this case each connector for connection with the external device will have 10 terminals, for example. In the case of digital signals, for example, each connector to be connected to the external device may then represent 1 byte, and in the case of 10 bundled individual wires additional signals can even be transmitted, e.g. two additional 1-bit signals, or the power supply of the byte with a plus and a minus signal conductor.
Instead of the connectors for connection to the external device, it is also possible for the individual wires to just appear from the end of the cable in order to be connected with the external device, and in this case the individual wires have to be connected to the external device bit by bit, for example.
Therefore, in order to reduce wiring errors, the individual wires and/or the cables with a plurality of individual wires bundled therein are marked with an appropriate inscription.
This already makes the connecting operation considerably easier and less susceptible to errors, however, faulty connections may still often result.
Accordingly, a code may as well be applied on the two complementary components, i.e. the components that are to be connected to each other, e.g. on the male connector and mating female connector, to provide for an assignment coding.
For example, DE 20 2008 004 800 U1 describes a system consisting of at least one switching device and at least one electrically switchable consumer and at least two connecting cables for directly or indirectly connecting the switching device and the consumer, wherein the system comprises at least one wiring unit for interconnecting the connection cables, and wherein plug-in connector elements of the connecting cables and at least two plug-in connection elements of at least one wiring unit to which the cables are connectable, are visually coded.